Strict null work on editorService

src/vs/workbench/common/editor.ts

@@ -760,9 +760,9 @@ export class TextEditorOptions extends EditorOptions {
 	private revealInCenterIfOutsideViewport: boolean;
 	private editorViewState: IEditorViewState | null;
 
-	static from(input?: IBaseResourceInput): TextEditorOptions | null {
+	static from(input?: IBaseResourceInput): TextEditorOptions | undefined {
 		if (!input || !input.options) {
-			return null;
+			return undefined;
 		}
 
 		return TextEditorOptions.create(input.options);

src/vs/workbench/services/editor/browser/editorService.ts

@@ -377,7 +377,7 @@ export class EditorService extends Disposable implements EditorServiceImpl {
 
 	//#region getOpend()
 
-	getOpened(editor: IResourceInput | IUntitledResourceInput, group?: IEditorGroup | GroupIdentifier): IEditorInput {
+	getOpened(editor: IResourceInput | IUntitledResourceInput, group?: IEditorGroup | GroupIdentifier): IEditorInput | undefined {
 		return this.doGetOpened(editor);
 	}
 
@@ -626,7 +626,7 @@ export class DelegatingEditorService extends EditorService {
 		this.editorOpenHandler = handler;
 	}
 
-	protected doOpenEditor(group: IEditorGroup, editor: IEditorInput, options?: IEditorOptions): Promise<IEditor> {
+	protected doOpenEditor(group: IEditorGroup, editor: IEditorInput, options?: IEditorOptions): Promise<IEditor | null> {
 		if (!this.editorOpenHandler) {
 			return super.doOpenEditor(group, editor, options);
 		}

src/vs/workbench/services/editor/common/editorService.ts

@@ -166,7 +166,7 @@ export interface IEditorService {
 	 *
 	 * @param group optional to specify a group to check for the editor
 	 */
-	getOpened(editor: IResourceInput | IUntitledResourceInput, group?: IEditorGroup | GroupIdentifier): IEditorInput;
+	getOpened(editor: IResourceInput | IUntitledResourceInput, group?: IEditorGroup | GroupIdentifier): IEditorInput | undefined;
 
 	/**
 	 * Allows to override the opening of editors by installing a handler that will